I had similar questions in the past - I have array with n elements in it, how can I get all combinations of two elements from it, without repeating?
Ie. if array is like this:
var arr1 = new[] { "A", "B", "C", "D", "E"};
... result should be
AB
AC
AD
AE
BC
BD
BE
CD
CE
CD
Can you help me please achieve this?
Consider the following Code...
var arr1 = new[] { "A", "B", "C", "D", "E" };
var combinations = new List<string>();
for(int i = 0; i < arr1.Length; i++)
{
for (int j = i + 1; j < arr1.Length; j++)
{
combinations.Add(string.Format("{0}{1}", arr1[i], arr1[j]));
}
}
Good Luck!
Added screenshot for reference...
ok, my feeble attempt:
var myArray = new[] { "A", "B", "C", "D", "E" };
var myCombos = new List<string>();
for (int i = 0; i < myArray.Length; i++)
{
for (int j = (i + 1); j < myArray.Length; j++)
{
myCombos.Add(myArray[i] + myArray[j]);
}
}
now we have:
AB AC AD AE BC BD BE CD CE DE
var arr1 = new[] { "A", "B", "C", "D", "E" };
var combinations = new List<string>();
foreach (var i in arr1) {
foreach (var j in arr1) {
if((int)i.ToCharArray()[0] < (int)j.ToCharArray()[0]) {
combinations.Add(i + j);
}
}
}
now the combinations list contains all combinations!
AB to be in the result as well as BA, while only AB is expected!
Maybe this little LINQ query:
var allCombinations = from str1 in arr1
from str2 in arr1
where str1.CompareTo(str2) < 0
select str1 + str2;
Console.Write(string.Join(",", allCombinations));
My last is different, i assume that was a typo in your result: AB,AC,AD,AE,BC,BD,BE,CD,CE,DE
Try following (cross join in LINQ)
var arr1 = new[] { "A", "B", "C", "D", "E"};
var result = (from i1 in arr1
from i2 in arr1.Where( i=> i[0]>i1[0])
select i1+i2).ToArray();
Snippet result on ideone here
AB
AC
AD
AE
BC
BD
BE
CD
CE
DE
DEnotCDCDtwice? And where isDE?